Question

对于我当前的项目，我需要有一个表格，其中包含每个单元格中的文本字段，单元格和文本字段的数量必须是动态的，这取决于MutuableArray中的数据数量。我在单元格中的文本字段工作，但我无法获取/设置文本字段值。我想知道你们是否可以帮助我或者至少纠正我的错误？非常感谢。请参阅以下代码段：

// Adds textfield into cell

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        NSUInteger row = indexPath.row;
        X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:row];
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

        BOOL bShowSelection = ([curIndex.HasVasteWaarden isEqualToString:@"false"]);

        if (bShowSelection) {
            bShowSelection = !([curIndex.DataType isEqualToString:@"Datum"]);
        }

        if ([indexPath section] == 0) {
            if (bShowSelection) {
                cell.accessoryType = UITableViewCellAccessoryNone;
            } else {
                cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;
            }

            UITextField *editField = [[UITextField alloc] initWithFrame:CGRectMake(110, 10, 185, 30)];
            editField.adjustsFontSizeToFitWidth = YES;
            editField.textColor = [UIColor blackColor];
            editField.placeholder = curIndex.Naam;
            editField.keyboardType = UIKeyboardTypeDefault;
            editField.returnKeyType = UIReturnKeyNext;
            editField.backgroundColor = [UIColor whiteColor];
            editField.autocorrectionType = UITextAutocorrectionTypeNo; // no auto correction support
            editField.autocapitalizationType = UITextAutocapitalizationTypeNone; // no auto capitalization support
            editField.textAlignment = UITextAlignmentLeft;
            editField.clearButtonMode = UITextFieldViewModeNever; // no clear 'x' button to the right
            editField.tag = [curIndex.UID intValue];

            [editField setEnabled: YES];
            [cell addSubview:editField];

            [editField release];
        }
    }

    return cell;
}

在某些情况下，我使用popovercontroller来显示数据列表。用户可以选择弹出窗口的值uit。选择值时执行此代码：

- (void)selectedValue:(NSString *) value {

    //---update value of the text field ---
    //The first attempt it doesn't put the text to text field

    //static NSString *CellIdentifier = @"Cell";
    //UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    //
    //if (cell == nil) {
    //  cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    //}

    // second attempt it crashes 
    X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:curRow.row];
    int index = [curIndex.UID intValue];
    UITextField *textField = (UITextField *) [curCell viewWithTag: index];
    if (textField) {
            [textField setText:value];
    }

    [textField release];

    [self.popOverController dismissPopoverAnimated:YES];
}

选择单元格时，我确保保存单元格以供日后使用。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:indexPath.row];

    if (!curIndex) {
        return;
    }

    curRow = indexPath; // saves the selected row

    if ([curIndex.VasteWaarden count] > 0) {
        UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
        curCell = cell; // saves the selected cell

        CGRect frame = [cell.superview convertRect:cell.frame toView:self.view];

        self.detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];          
        detailViewController.delegate = self;
        self.popOverController = [[[UIPopoverController alloc] initWithContentViewController:detailViewController] autorelease];               

        X10ArchiefIndexDefs *curIndex = [indexDefinities objectAtIndex:indexPath.row];
        self.detailViewController.Values = curIndex.VasteWaarden;

        [self.popOverController presentPopoverFromRect:frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    }
}

再次感谢很多事。

干杯， Inoel

Answer 1

在第二个代码段中，您将释放textField。你不应该这样做，因为你没有保留它。由于viewWithTag: simple获取对文本字段的引用，因此它不会保留textField。因此，您释放的次数已经保留了多次，因此retainCount达到0并且文本字段从内存中释放。然后当你第二次尝试它时，内存中没有文本字段。

只需删除：

[textField release];

来自第二个代码段。如果你不明白为什么，那么请阅读一些关于内存管理的文章（只是谷歌吧）。完全理解它需要一些时间，至少我知道它花了我一段时间:)）

在表格单元格中获取/设置UITextField值

1 个答案: